The present invention relates to an apparatus for positioning a workpiece in a predetermined angular position with respect to a rotatable drive spindle.
When manufacturing a cam shaft, it is necessary to maintain the workpiece in a fixed angular relation with respect to a master cam shaft so that the lobes on the finished product are in proper angular relation with one another. The master cam and the drive spindle rotate in synchronism, thus the workpiece may be maintained in the proper relationship with the master cam by making it rotate with the drive spindle. Various work drives have been devised to accomplish this end.
In a known device, a pair of opposing lock surfaces engage a key which extends from a slot in the workpiece. Both of the lock surfaces are pivotably mounted to a backing plate of the known device, and springs actuate them to engage the key. U.S. Pat. No. 3,667,167 discloses such a device.
The workpiece may be positively located with respect to a rotatable drive spindle using a device like that disclosed in U.S. Pat. No. 2,984,955. In this device the drive spindle extends outward from a drive plate to engage a conical recess located in the end of a longitudinally extending workpiece. The workpiece is rotated about its axis by the drive spindle, and a pin is mounted in the drive plate at a location radially spaced from the spindle. The pin may be moved axially to engage a second recess in the workpiece in order to locate the workpiece in a predetermined angular position with respect to the spindle and drive plate.